Which Windows Vista is for me?

I'm planning on getting Windows Vista for my mac pro, but I'm confused which version of Windows Vista because there is too many. I have narrow it down and I think Windows Vista Ultimate will suit me best. However, there is 2 versions of it. One is x64 and the other is x86 version. What is the best one to get? What is the different between this two? My Mac Pro use a 64 Bit Processor, so I would think x64 is make more sense? I want the version that work like Windows XP Pro Edition, in term of more drivers and softwares compatibility.

Well... you're going to have software/driver compatibility problems with the first release of Vista no matter what edition you get. I don't think any edition of Vista is more limiting in that regard.

According to Paul Turott, "you don't need to buy a x64-specific versions of Vista. Instead, all Windows Vista editions, except for Vista Starter, will come with both 32-bit (x86) and 64-bit (x64) versions in the box, on separate DVDs."

You can read the rest of it here at Windows Vista Feature Focus: 64-Bit (x64) Support. It's from May 2006, so it may be out of date information, but I don't know. As with WinXP, though, "32-bit device drivers are not supported, so you can't use any of the existing hardware drivers out there, but must instead use the subset of x64-based drivers out there."

Ultimately unless you really know you need 64-bit, it's probably a good idea to stick with the regular version.

So I won't benefit any speed from x64 version because my Mac Pro is 64 Bits? Sorry, I'm kinda noob at this Computer stuff. I think I will get the 32 Bits version. Have any one try out Windows Vista on a Mac Pro yet? How it is in term of Drivers and Software compatibility and speed?

Unless you have a windows application you want to run, and it is optimized for 64 bit, do yourself a favor and stay away from it. I bought a couple XP 64 workstations and have fought driver issues ever since. Well, not quite. I gave the machines to some other users who are not allowed to alter the HW/SW. Now they are fairly stable. As for performance gain, never discerned any.

MacRumors attracts a broad audience
of both consumers and professionals interested in
the latest technologies and products. We also boast an active community focused on
purchasing decisions and technical aspects of the iPhone, iPod, iPad, and Mac platforms.